Guide roller for wires

ABSTRACT

A guide roller for wires, comprising a coating support ( 1 ) in the form of a hollow cylinder which is slidable parallel to the longitudinal direction, on which a coating ( 4 ) is fixed permanently by adhesion, and having guide grooves for the wires, and which is supported on a hub part by a stabilising support ( 2 ) made from CFP or metal, wherein the coating support ( 1 ) is made of CFP and is secured on the stabilising support ( 2 ) only by a cylindrical or conical press-fitting, avoiding the use of a screw connection

The invention relates to a guide roller for wires comprising a coating support in the form of a hollow cylinder which is slidable in the longitudinal direction and is supported on a hub part by a cylindrical stabilising support made from carbon fibre-reinforced plastic (CFP) or metal.

BACKGROUND OF THE INVENTION

A guide roller for wires of such kind is known from DE 197 17 379 A1. In this case the coating support is made from invar steel and is fixed by shrink fitting on a stabilising support made from a material with a substantial coefficient of linear expansion. In order to slide the coating support on to or off of the stabilising support, at least the stabilising support must therefore be cooled to a correspondingly substantial degree, necessitating significant technical effort. Furthermore, the document describes a construction in which the coating support and the stabilising support are screwed together. Here too, mounting and removing the coating support is associated with relatively intensive effort. Moreover, it is difficult to obtain good radial run-out with this device.

BRIEF DESCRIPTION OF THE INVENTION

The object of the invention is to suggest a guide roller for wires that is easy to manufacture, in which the coating support is easy to mount and remove, and which has good radial run-out. Subsequently, it must also be easy to mount and remove while retaining good tolerances in terms of shape and position.

This object is solved according to the invention with the characterizing features recited in claim 1. The subordinate claims refer to advantageous embodiments thereof.

In the guide roll for wires according to the invention, it is provided that the coating support is made from CFP and is attached to the stabilising support via a press fitting, without the use of a threaded connection. Since the stabilising support is functionally decoupled from the coating support, coating may be carried out without the need to approach the coating site with the stabilising support. The coating support is mounted on the stabilising support in directly usable condition in the manner of a module and may then be put into operation immediately.

The stabilising support may be of very rigid construction and may be made from either CFP or metal. Together with the hub part, it has excellent strength and dimensional stability.

The coating support may be mounted axially onto the stabilising support and removed therefrom very easily using a press at normal temperature. It is not necessary to create a temperature difference between the parts that are to be connected. Even so, the requisite turning moments can be transferred from the stabilising support to the coating support without difficulty, and excellent radial run-out is assured from the outset and under all operating conditions.

Since the coating support is made from CFP, it is possible to create extremely precise fits, definable in advance, in the area of the cylindrically shaped mutual contact surfaces of the two parts. This not only makes storage easier, it also provides the additional capability to produce pre-coated and pre-assembled coating supports as parts for one-time use and transport them to the site where they are to be used.

The coating supports and the stabilising supports are in contact with one another via cylindrical surfaces. In such a construction, the coating support may be mounted on and removed from the stabilising support in either of the two possible directions.

The coating support and the stabilising support may be in contact with one another via conical surfaces. In the case of a construction of this kind, mounting and removal can only take place in one, predefined direction. However, the advantage of this arrangement is that the inner surface of the coating support is subject to less wear during mounting and removal. The conical surfaces should be at an angle between 0.001 and 5°, preferably an angle between 0.002 and 0.05°, relative to the longitudinal axis.

The coating may consist of a polymer or ceramic material. The material used for preference is elastomeric polyurethane that has been applied to the coating support in a casting process and is furnished with the necessary channels for guiding the wires according to its intended application. The materials used must always demonstrate the necessary chemical, thermal and mechanical resistance during its intended use, and in particular good resistance to the effects of glycol.

In the embodiment according to claim 2, it is provided that the coating support is made from fibre stands stuck together with synthetic resin and arranged one on top of the other in multiple plies, and aligned at an angle of +/−30 to 60° relative to the longitudinal axis of the hollow cylinder, the fibre strands in the consecutive layers in the radial direction intersecting with one another in the opposite direction. In this way, the stiffness and stability necessary for mounting and removal is assured in both the circumferential and the longitudinal directions, and the coated coating support may be used equally well regardless of its mounting direction. The Poisson's ratio resulting from this also makes it easier to mount the coating support.

The coating support is preferably made from fibre strands that are stuck together with synthetic resin, arranged one on top of the other in multiple plies and aligned at an angle of +/−40 to 50° relative to the longitudinal axis of the hollow cylinder, the fibre strands in the consecutive layers in the radial direction intersecting with one another in the opposite direction.

In addition, the coating support may also contain at least one layer in which the fibre strands are arranged at an angle of 80 to 90° relative to the longitudinal axis of the hollow cylinder. The peripheral layer formed thereby lends the coating support particularly good stiffness and stability in the circumferential direction, which is beneficial for enabling the transfer of high turning moments from the stabilising support to the coating support. In addition, dimensional stability is supported, which helps substantially to ensure good positional precision of the grooving arrangement.

If both the stabilising support and the coating support are made from CFP, they may have constructions differing from each other reflecting their different technical functions. In this context, the overall radial thickness of the stabilising support is at least three times greater than that of the coating support. The overall thickness of the stabilising support is preferably at least five times greater than that of the coating support. The differing overall thicknesses reflect the fact that the stabilising support is dimensioned primarily from the point of view of the bending load it has to withstand, and the coating support is primarily dimensioned to satisfy the requirements of the press-fit seating. The stabilising support and the coating support are able to complement one another particularly well after mounting through the properties these constructions lend to them.

If the stabilising support is made from metal, particularly steel, the wall thickness is also considerably greater than that of the coating support.

Without the coating, the coating support advantageously has a wall thickness that is between 0.5 and 8% of its outer diameter, preferably between 1 and 3% of its outer diameter. Within the indicated ranges, a lightweight coating support may be produced, coated and treated easily and with low production costs. Thus it is also possible to convert existing guide rollers of conventional construction for the purposes of the invention and to equip them with a coating support that is intended for single use only, and is furnished with the pre-grooved coating for wires that is specified therefor and affixed by adhesion. In this case, used coating supports that have become worn no longer need to be returned for re-application of a coating and grooving.

The flanges on the frontal surface may either be in flush contact only with the radial inner side of the stabilising support or they may be provided with a circumferential collar that covers the frontal surfaces of the stabilising support. The collars should have the same outer diameter as the stabilising support. This makes it easier to mount the tubular coating support on the stabilising support repeatedly without causing mechanical damage to the frontal ends of the stabilising support. In particular, this prevents the fibre or plastic components from becoming detached from the CFP material and being carried into a gap that is formed between the coating support and the stabilising support.

The stabilising support may be braced radially between the flanges on the frontal surfaces by at least one further flange. This prevents oval deformations from occurring under one-sided loads.

The flanges and the stabilising support are advantageously also affixed by adhesion with synthetic resin, and are thus attached to each other immovably. If the stabilising support is made from metal, it is practical to weld the parts together similarly.

The stabilising support is advantageously delimited by a surface that has been calibrated with rotational symmetry on the outside in a grinding process and has a slightly conical or cylindrical shape. This helps to achieve a press fitting that is sufficiently tight but still detachable.

The inner cylindrical surface of the coating support is calibrated extremely precisely anyway, due to the manufacturing process. Production is effected in a winding process, in which the fibre strands, soaked in synthetic resin are wound onto a conical or cylindrical mould core and are fixed permanently by the subsequent solidification and curing of the synthetic resin.

The coating support may be delimited on the outside by a cylindrical surface that has advantageously been calibrated with a “peel ply” in the winding process, and has been also been roughened in the same process. Such a cylinder surface is produced in a final process step by winding a polyamide tissue without synthetic resin or a similar material onto the as yet non-rigid, final winding ply of resin-soaked CFP and forcing it into the last winding ply by prestressing. This also forces the excess synthetic resin radially outwards through the mesh of the fabric, so that a fabric-like surface structure is obtained on the outside of the coating support, which remains as the CFP mantle cures, and when the fabric is removed by peeling leaves a good adhesion base for the coating that is applied, subsequently.

The outermost ply of the coating support may be calibrated and roughed as well or additionally thereto in a grinding process after curing. This makes is possible to apply an extremely precisely dimensioned coating of elastomeric polyurethane to the coating support and to embed the coating in the roughened surface of the coating support particularly firmly. The coating may be applied in a casting process.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In the following, the invention will be explained in greater detail on the basis of exemplary embodiments and with reference to a drawing. In the drawing:

FIG. 1 shows a longitudinal section through a guide roller for wires

FIG. 2 shows a longitudinal section through a corner area of the guide roller for wires shown in FIG. 1.

The guide roller for wires of which a longitudinal section view is represented in FIG. 1 is intended for separating thin slices of a hard material, for example a silicon crystal, with the aid of wires. In this context, a wire, possibly coated with diamond dust or a wetted with a cutting emulsion is looped together in several windings round two or more parallel-axle rollers and the hard material is cut and separated into thin slices at several adjacent and parallel points simultaneously by the wire. For this purpose, the rollers are equipped with a coating support, the outside of which has a polyurethane coating 4 adhering permanently thereto. Coating 4 is provided with grooves extending circumferentially for guiding the wire.

Coating support 1 is in the shape of a hollow cylinder and is supported on a hub part by a stabilising support 2 made from CFP or steel, which also has the form of a hollow cylinder. It is provided that coating support 1 is made from CFP and is secured on stabilising support 2 only by press-fitting, without the use of screws or shrink fitting, and that the hub part is in contact with the inside of the stabilising support via radial flanges at least in the area of the frontal surfaces. Coating support 1 consists of fibre strands that are stuck together with synthetic resin and arranged one on top of the other in multiple plies and are aligned at an angle of +/−30 to 60° relative to the longitudinal axis of the respective hollow cylinder, the fibre strands arranged in the consecutive layers in the radial direction intersecting with one another in the opposite direction. The preferred angle is +/−40 to 50°. Additionally, one layer of fibres extending essentially circumferentially is contained in coating support 1 particularly to increase stiffness and stability in the circumferential direction. Accordingly, there is no likelihood of relative shift of the coating support even during prolonged use.

The coating support may be used irrespectively of its direction of rotation, which simplifies mounting considerably. Mounting and removal may be carried out at a normal temperature by mounting the pre-coated, ready-to-use coating support on the stabilising support and removing it therefrom with the aid of a press. In order to fix the coating support, it is not necessary to screw the coating support nor does a special material pairing have to be used with respect to the coating support and the stabilising support, and temperature ranges that may possibly cause the parts to become separated due to the different coefficients of thermal expansion of the coating support and the stabilising support do not have to be avoided in normal use. This significantly simplifies the production, mounting and removal of the tubular coating support as well as the use of the ready-to-use guide roller for wires. At the same time, the roller demonstrates excellent radial run-out.

Because of their differing functions, stabilising support 2 and coating support 1 are also constructed differently, provided that the radial layer thickness of stabilising support 2 is at least three, preferably at least five times greater than that of coating support 1. The radial layer thickness of the stabilising support may be 20 to 60 mm depending on the length of the guide roller for wires.

Without the coating, the coating support has a wall thickness equal to 1 to 3% of its outer diameter. As a result, it may be manufactured, coated and mounted without difficulty.

The flanges on the frontal faces of hub part 3 are joined flush with the inner circumference of stabilising support 2 by adhesion or welding. The stabilising support may thus be made from CFP or steel.

If the flanges and stabilising support 2 are stuck together using synthetic resin, it is practical to use a resin that is chemically compatible with the resin used to stick the fibre strands of the coating support and the stabilising support together.

The stabilising support may be braced between the metal flanges on the frontal surfaces by at least one further metal flange to prevent oval deformations from occurring under the pressure of prolonged one-sided loads. The number of additional flanges may be altered according to needs.

Stabilising support 2 is delimited on the outside by a cylindrical surface 2.1, which is calibrated by a grinding process. In this context, it would not be difficult for one skilled in the art to fix the diameter set in the grinding process such that a secure press fitting is obtained, ensuring that the coating support does not twist or shift undesirably on the stabilising support during normal use, yet still allows the coating support to be slid off of the stabilising support in the longitudinal direction with the aid of a press when necessary.

If an existing guide roller for wires is to be converted in a manner envisaged by the invention, any coating that is already present thereon is removed and the outer diameter is calibrated in accordance with the explanations given in the preceding.

Coating support 1 is delimited on the outside by a cylindrical surface 1.1, which has been given a fabric structure by a peel ply that has been removed previously and/or has been calibrated and roughed in a grinding process to ensure that the polyurethane coating is particularly securely embedded and to enable the profile of the coating to be formed extremely precisely.

The features of the invention disclosed in the preceding description, the claims and the drawing may be pertinent either individually or in any combination for the realisation of the invention in its various embodiments. 

1. A guide roller for wires, comprising: a coating support in the form of a hollow cylinder which is slidable parallel to the longitudinal direction, on which a coating is fixed permanently by adhesion, and having guide grooves for the wires, and which is supported on a hub part by a stabilising support made from CFP or metal, wherein the coating support is made of CFP and is secured on the stabilising support only by one of a cylindrical and conical press-fitting, avoiding the use of a screw connection.
 2. The guide roller for wires as recited in claim 1, wherein the coating support and the stabilising support consist of fibre strands stuck together with synthetic resin, which are arranged in multiple plies one on top of the other and are aligned at an angle of +/−30 to 60° relative to the longitudinal axis of the hollow cylinder, wherein the successive fibre strands in the radial direction intersect each other in the opposite direction.
 3. The guide roller for wires as recited in claim 1, wherein the coating support and the stabilising support consist of fibre strands stuck together with synthetic resin, which are arranged in multiple plies one on top of the other and are aligned at an angle of +/−40 to 50° relative to the longitudinal axis of the hollow cylinder, wherein the successive fibre strands in the radial direction intersect each other in the opposite direction.
 4. The guide roller for wires as recited in claim 2, wherein the coating support and/or the stabilising support comprise at least one ply that consists of fibre strands stuck together with synthetic resin and extends essentially in the circumferential direction.
 5. The guide roller for wires as recited in claim 1, wherein the stabilising support and the coating support have constructions that differ from one another, providing that the radial layer thickness of the stabilising support is at least three times greater than that of the coating support.
 6. The guide roller for wires as recited in claim 1, wherein the stabilising support and the coating support have constructions that are the same as one another, providing that the radial layer thickness of the stabilising support is at least five times greater than that of the coating support.
 7. The guide roller for wires as recited in claim 1, wherein the coating support has a wall thickness equal to 0.5 to 8% of the associated outer diameter.
 8. The guide roller for wires as recited in claim 1, wherein the coating support has a wall thickness equal to 1 to 3% of the associated outer diameter.
 9. The guide roller for wires as recited in claim 1, wherein the hub part is in contact with the stabilising support at least radially from the inside at least in the area of the frontal face ends thereof via radial flanges.
 10. The guide roller for wires as recited in claim 1, wherein each of the frontal face flanges of the hub part is furnished with a collar protruding radially outwards and that the collars cover the frontal face of the stabilising support.
 11. The guide roller for wires as recited in claim 10, wherein the collars are delimited on the outside by circumferential surfaces that progressively and continuously complete the circumferential surface of the stabilising support in the manner of a notional extension.
 12. The guide roller for wires as recited in claim 1, wherein the stabilising support is supported between the frontal face flanges by at least one additional flange of the hub part.
 13. The guide roller for wires as recited in claim 1, wherein the flanges of the hub part and the stabilising support are stuck together with synthetic resin or welded together.
 14. The guide roller for wires as recited in claim 1, wherein the stabilising support is delimited on the outside by a cylindrical surface that is calibrated by a grinding process.
 15. The guide roller for wires as recited in claim 1, wherein the coating support is delimited on the outside by a cylindrical surface that is calibrated by a grinding process.
 16. The guide roller for wires as recited in claim 15, wherein the cylindrical surface is provided with a relief-type profile by a grinding process and/or by a peel ply.
 17. The guide roller for wires as recited in claim 1, wherein the coating support with the fixed coating securely attached thereto and the guide grooves for wires incorporated therein is intended for one-time use only. 